An English Copper And Brass Dive Helmet By Siebe, Gorman & Co., London The bulbous spherical head piece with protruding valves and outlets centred to the front by a removable glazed window, having two further grated windows to either side, the curved shoulder piece joined by heavy brass screws bearing the brass plate 'Siebe, Gorman & Co Ltd, Submarine Engineers, London, Patent,' 50 cm high.